Browsing by Author "Tung, Ting-Wei"

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Room-temperature-operated organic-based acetone gas sensor for breath analysis
(2018-05-01)
Chuang, Ming-Yen
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Lin, Yu-Ting
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Tung, Ting-Wei
;
Chang, Liang-Yu
;
Zan, Hsiao-Wen
The major merits of organic-based sensors include their low cost, room-temperature operation, and small size. However, their sensitivity and selectivity are concerning, especially in the application of breath analysis. In this work, organic-based sensors were developed based on cylindrical nano-pore structures, which enhanced the sensitivity down to ppb levels. The sensing performance was demonstrated both in pure nitrogen and ambient air. The sensor constructed with poly[(9,9-dioctylfluoreny1-2,7-diy1)-co-(4,41(N-(4-sec-butylphenyl)diphenylamine)] (TFB) exhibited a 5% sensing response to 300 ppb of acetone in ambient air. In addition, the sensor's response to other major breath components, including nitric oxide, ethanol, carbon dioxide, and ammonia, was also established. The results showed that the TFB sensor also exhibited a good response to ammonia. Therefore, a humidification tube was designed as an ammonia filter to improve selectivity. The concept of integrating a highly sensitive sensor with a customized sensing system shows promise for medical applications. (C) 2018 Elsevier B.V. All rights reserved.
UV-enhanced room-temperature ultrasensitive NO gas sensor with vertical channel nano-porous organic diodes
(2020-10-01)
Madhaiyan, Govindasamy
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Tung, Ting-Wei
;
Zan, Hsiao-Wen
;
Meng, Hsin-Fei
;
Lu, Chia-Jung
In this work, we successfully proposed an organic semiconductor gas sensor on vertical channel design to exhibit an ultra-sensitive response to nitric oxide gas (10 ppb) at room temperature. The effect of ultra-violet (UV) irradiation (lambda =365 nm) on sensing performance of solution processed vertical organic diode (VOD) has been investigated. After implementing a simple and low-cost UV treatment, the sensing response of PBDTTT-C-T based NO sensor is significantly enhanced from 93 % to 233 % at 1 ppm. In addition, we also introduced a new strategy to tune the selectivity of organic gas sensors by using photochromic molecule and organic semiconductor blends. With the 1 Wt% spiropyran dopant, the sensor response to ammonia can be considerably suppressed, hence the response ratio between NO and ammonia can be improved from 2.9 to 16.0, indicating an improved selectivity. The proposed ultrasensitive and selective NO gas sensor have great potential for exhaled breath detection (asthma patients) and environmental monitoring.